Browsing by Author "Hamza, Nermeen"

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    Effect of Amalgam Corroded Products on Quality of Hybrid Layer Using Etch and Rinse and Self-etch Adhesive Systems
    (IJISET, 2019-05) Abdelnabi, Ali; Hamza, Nermeen
    Amalgam and resin composite are two commonly used restorations in dental practice. Nowadays replacing the silver colored dental amalgam with the tooth colored composite has become a routine procedure. Amalgam ages in the oral environment leaving corrosive products that infiltrates into tooth structure and might interfere with bonding of resin composite to tooth on replacing amalgam with composite. In this study 40 molars were selected, cavities were made in each molar and filled with amalgam. Teeth were stored in distilled water for one year. After storage teeth were divided into two main groups; group A; where amalgam was removed without any further increase in cavity depth. Group B; where amalgam was totally removed followed by further increase in cavity depth by 0.5 mm. Each group was sub divided into 2 groups according to the adhesive system used in re-filling the cavities where sub group 1; cavities re-filled using self-etch adhesive and resin composite. Group 2 cavities re-filled with etch and rinse adhesive and resin composite ·Teeth examination: slicing of teeth was done, slices were examined using scanning electron microscope coupled with EDAX. The results of this study demonstrated that amalgam corrosive products interfered with bonding and that removal of 0.5 mm showed no corrosive remnants and allowed better adhesion for both adhesive systems used.
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    Effect of two different Materials; Microgel p(NIPAM) and Sodium Fluoride on the Depth and Degree of Occlusion of the Dentinal Tubules at Different Dentin Depths
    (Biocore Group, 05/05/2021) Hamada, Salma Basyouni; Hamza, Nermeen; Mohsen, Reham; Kamel, Faten
    Objectives: To evaluate the effect of two different desensitizing materials microgel p(NIPAM) and 5% sodium fluoride (NaF) on the degree of occlusion and depth of penetration of the dentinal tubules on superficial and deep dentin after immediate application and thermocycling using environmental scanning electron microscope. Materials and Methods: 20 non- carious, non-restored molars were included. Each tooth was cut in order to obtain four quadrants. Specimens were divided into two groups according to aging. Then they were further sub-divided into two subgroups according to dentin depths. Further subdivision into four divisions according to the desensitizing material. The specimens were evaluated for the depth of penetration and degree of occlusion of each material using environmental scanning electron microscope. One-way ANOVA followed by Tukey post hoc test was used to compare between more than two groups in non-related samples. Independent sample t-test was used to compare between two groups in non- related samples. Results: p(Nipam) showed the highest mean value without statistically significant difference with the varnish group regarding the degree of occlusion, either on immediate evaluation or after thermocycling. Conclusion: Better occlusion of dentinal tubules was shown on immediate testing rather than after thermocycling regardless the dentin type, however, more depth of penetration was shown after thermocycling regardless the dentin type. All the desensitizing materials showed better occlusion and depth of penetration in superficial dentin than in deep dentin. Clinical relevance: p(NIPAM) microgel is a promising material in the treatment of dentin hypersensitivity, however further in-vivo studies are needed.